Tuberculosis (TB) is an airborne bacterial infection. It usually occurs in the lungs, but it can spread anywhere through the bloodstream or lymph nodes. TB may remain inactive until the immune system becomes compromised, at which point it can cause tissue death within organs and be potentially deadly if untreated. Antibiotics have made this once-widespread condition rare. Symptoms include coughing, trouble breathing, fatigue, fever, sweating, and more. Treatments depend on whether you have inactive, active, or multidrug-resistant TB. Follow the links below to find WebMD's comprehensive coverage about how tuberculosis is contracted, how to treat it, and much more.